User guide
Chapter 9 Creating Charts from Data 149
Showing Trendlines in Charts
Trendlines are lines calculated and drawn to t your data, according to the type of
equation you prefer. You can display trendlines for most chart types, except stacked
bar, column, and area charts and pie charts.
To show a trendline for the data points in a selected series:
1 Select the series for which you want to show a trendline, and then click the Inspector
button in the toolbar.
2 Click the Chart inspector button, and then click Series.
3 Click Advanced at the bottom of the Series pane. Then click Trendlines.
4 Select, from among the following, the type of equation you want to use to calculate
the trendline:
Linear: Produces a best-t straight line, most useful for simple, linear data series.
Logarithmic: Produces a best-t curved line, most useful when values increase or
decrease quickly, then level out.
Polynomial: Produces a curved line that has hills and valleys to show where values
rise and fall. Specify the order of polynomial you want to use in the Order eld; order 4
produces as many as 3 hills or valleys.
Power: Produces a curved line for use when you want to compare measurements
that increase at a specic rate. Power can’t be used with data that contains zero or
negative values.
Exponential: Produces a curved line for use when values rise or fall at increasingly
higher rates. Exponential can’t be used with data that contains zero or negative values.
Moving Average: Produces a trendline using the number of data points you specify
in the Period eld, averages them, and uses the average value as a trendline point.
Specify the period you want to use in the adjacent eld.
5 To see the equation that describes a trendline, select the line, and then select Show
Equation. You can drag this equation to wherever you want it to appear on the slide.
6 To see the R-squared value that was used to calculate a trendline, select the line, and
then select Show R^2 Value. You can drag this number to wherever you want it to
appear on the slide.
7 To display a label for a trendline, select it, and then select Label. Type a label in the
adjacent eld.
8 To change the line color or thickness, select it, and then click the Graphic button
in the Inspector window. Make adjustments using the Stroke controls of the
Graphic inspector.